DB-GPT builds the destination path for an uploaded skill from the multipart filename without constraining it to the upload directory

Overview

DB-GPT builds the destination path for an uploaded skill from the multipart filename without constraining it to the upload directory. skill_upload in packages/dbgpt-app/src/dbgpt_app/openapi/api_v1/agentic_data_api.py takes file.filename as given and writes the request body to upload_dir / filename. A path composed with that operator discards the left operand when the right one is absolute and follows parent references otherwise, so a filename such as ../../../tmp/x or /tmp/x resolves outside the intended directory; nothing canonicalises the result, checks that it remains under the upload root, or prevents a .py suffix. The route's only dependency is get_user_from_headers in dbgpt_serve/utils/auth.py, which returns a request carrying the admin role whether or not a user_id header is supplied, so the endpoint is reachable without credentials. A remote attacker holding no account can therefore write attacker-controlled bytes to any path the server process can write, place a new Python module inside the application package or replace one the application already imports, and obtain code execution in the server process when that module is next imported.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.